1. Field of the Invention
This invention relates to a thread-wound golf ball which is improved in flying distance and hitting feel.
1. Prior Art
The R&A Standards prescribe that golf balls shall have a diameter of at least 42.67 mm and a weight of at most 45.93 grams. The upper limit of diameter and the lower limit of weight are not specified. Any golf ball meets the Standards as long as it is 42.67 mm or larger in diameter and 45.93 grams or lower in weight.
However, in general practice, since it is desired for golf balls to reduce the aerodynamic resistance on trajectory for improving the flying performance, golf balls are manufactured such that they are small enough, but the ball diameter is not smaller than 42.67 and they are heavy enough, but the ball weight does not exceed 45.93 grams. More particularly, thread-wound golf balls are generally manufactured by winding thread rubber on a center having an outer diameter of 26 to 32 mm and a weight of 17 to 22 grams to form a wound core, which is covered with a resin to a thickness of 1.5 to 2.0 mm.
These wound golf balls are good in feeling and controllability, but they travel less distance when hit by less powerful players. Also undesirably, when hit off center, the wound balls are receptive to extra spin components like side spin, which detract from the flying distance.
A number of two-piece golf balls are now on the market. They are characterized by an increased flying distance as compared with the wound golf balls. This tendency becomes salient in slow head speed regions. With a choice of two-piece golf balls, less powerful players will be satisfied with an increased flying distance. However, the two-piece golf balls are poor in hitting feel because of hardness as compared with the wound golf balls and tend to roll further on the green because of minimized spin.
Therefore, golf balls which provide a pleasant feeling on impact and good control-lability like the wound golf balls and offer a substantial flying distance like the two-piece golf balls are desirable for less powerful golfers and golfers who swing at a low head speed.